From some days I'm having this strange noise coming from my car. It's constant and I seems like sth is scratching or like a fan that flies. I have recently changed oil and filters and also changed the butterfly.
Thank you for your patience.
Remove the serp belt and start the engine (only for a few seconds) to see if the noise is coming from one of the accessories. NOTE: The engine will overheat with the belt off, so only run it a short time.